Corresponding fluorescent 3-aryl-1-acyl-1,6-dihydro-6-indolyl-1,2,4-triazine-5(4Н)-ones were synthe-sized with using of nucleophilic substitution of hydrogen methodology by means of reaction 3-aryl-1,2,4-triazine-5(4Н)-ones with indols in the presence of naproxen. Obtained compounds demonstrate intensive fluorescence quenching in the presence of nitroaromatic compounds (2,4-dinitrotoluene, 2,4,6-trinitrophenole (picric acid)).